I think the PostgreSQL Development Group does a great job overall. If they indeed have a reputation of being hard to work with, all the better in my opinion if it means guarding the integrity of the Project.
That's a big "if." There are many projects that have been controlled by "hard to work with" developers, and it's not always a good thing. Even if the project doesn't suffer significantly from it, that doesn't mean it's helping the project either.
That may not be the case here, but just as a general statement, you can't chalk up "hard to work with" as equating to "focused on quality" and/or "good for the project."
> If someone is too difficult to work with, the rest will just fork and move on with life.
This is a gross simplification.